Winder control

ABSTRACT

A winder control for programming the torque to be applied by a winder to effect winding of material into a roll wherein the tension applied to the material to be wound is dependent upon the instantaneous radius of the roll of wound material, the winder includes first sensing means for sensing the angular velocity of the roll of material and producing a signal indicative thereof, second sensing means for sensing the linear velocity of the material to be wound, and producing a signal indicative thereof, and divider means for generating a signal indicative of the instantaneous radius of the roll of wound material. The radius signal is directed to means for multiplying the instantaneous radius signal by a factor indicative of the desired tension to be applied to the material when the roll of material has a predetermined radius. This establishes a torque signal indicative of the torque the winder must apply to the roll of material to obtain the predetermined tension in the material to be wound at the instantaneous radius calculated by the divider means.

United States Patent 11 1 OCallaghan et al.

[ Oct. 7, 1975 WINDER CONTROL [75] Inventors: Gerald F. OCallaghan; John M. Haurykiewicz, both of Kenosha,

21 Appl. No.: 317,350

Primary ExaminerJohn W. l-luckert Assistant Examiner-John M. Jillions Attorney, Agent, or FirmTeagno & Toddy [57] ABSTRACT A winder control for programming the torque to be applied by a winder to effect winding of material into a roll wherein the tension applied to the material to be wound is dependent upon the instantaneous radius of [52] U.S. Cl 242/7551; 318/6 h ll of Wound ma ri l, the winder includes first [51] Int. C1. B6511 23/20; B6511 77/00 en ng means f r sen ing the angular velocity of the [58] Field of Search 242/7551, 75.52, 75.44, roll of material and producing a signal indicative 242/7545, 75.47, 186, 187, 188, 191; 318/6, thereof, second sensing means for sensing the linear 7 velocity of the material to be wound, and producing a signal indicative thereof, and divider means for gener- [56] References Cited ating a signal indicative of the instantaneous radius of UNITED STATES PATENTS the roll of wound material. The radius signal is di- 2,874,917 2/1959 Pell 242/7551 i i to means for m i i the msta'ltaneous 3,114,850 12/1963 3.18/6 X dius signal by a factor indicative of the desired tension 3,348,107 10/1967 Hamby 242/7551 x be aPPhed to the malerla' when the of materlal 3,372,320 3/1968 Boyum et al 242/7551 x has a predetermined radius- This establishes a torque 3,548,270 12/1970 Silva 318/6 g al in at of th t rque th winder must apply 3,749,331 7/1973 Nedreski.... 242/7551 to the roll of material to obtain the predetermined ten- 3,749,989 7/1973 Pittner 242/75.44 ign in the material to be wound at the instantaneous FOREIGN PATENTS OR APPLICATIONS radius calculated by the divider means.

1,175,407 12/1969 United Kingdom 318/6 17 Claims, 4 Drawing Figures 2 /Z /6' U/VW/ND 6, PRUC ZSZY Tl PPM 32 eaawcz/em/r l' 4 flP/VE ffl 1' J a? mvs/av 2,6

f cueeswr *cwreouae T L I l l 29. J 00/4 CWfiRE/VT L 36 7752292 7217 5 i-l c CURRENT P5593467? US. Patent Oct. 7,1975 Sheet 2 Of3 3,910,521

v m fik L a .NQRQ U I W iv o U.S. Patent Oct. 7,1975 Sheet 3 of 3 3,910,521

TORQUE REFREA/CE ($0MPU7'E0 RAD/U6) FULL 50/40 up AA0/(/S 29 (/0 x CORE) WINDER CONTROL BACKGROUND OF THE INVENTION The present invention relates to a winder control for controlling the torque generated by a winder for effecting the winding or unwinding of a web or filament of material wherein the tension of the material to be wound is controlled as a function of the instantaneous radius of the wound material.

Known winder controls utilized a drive mechanism to control the tension applied by the winder to the material to be wound. The known controls generally utilized a closed loop system in which a tension feedback signal, indicative of the actual tension applied by the drive, was modified by a radius signal and the modified tension signal directed to a torque or current control to program the control so that the desired taper of tension was maintained. The present invention provides an open loop winder control wherein the instantaneous radius of the wound material is calculated by an analog divider. This instantaneous radius signal is utilized to program a torque or current control to establish the proper taper of tension. A tension feedback signal is not provided as in known winder controls and the instantaneous radius signal acts to progam the torque or current control to maintain the proper taper of tension. In this way, a simpler, more reliable, and less expensive winder control is provided for controlling the torque generated by a drive.

SUMMARY OF THE PRESENT INVENTION The present invention provides a new and improved winder control for controlling the torque generated by a winder to thereby control the tension on the material to be wound or unwound so that the tension is automatically controlled in response to the radius of the wound material. The winder control includes a first sensing means for generating a signal indicative of the angular velocity of the wound material, a second sensing means for generating a signal indicative of the linear velocity of the wound material and divider means for establishing a signal indicative of the instantaneous radius of the wound material. The signal indicative of the instantaneous radius of the wound material is multiplied by a taper potentiometer which establishes a signal indicative of the taper of tension as a function of the instantaneous radius of the wound material. The taper of tension signal is combined with an inertia compensation signal and a friction compensation signal to establish a signal indicative of the torque to be applied to the roll of material by the winder. The torque signal is directed to a current control which controls the energization of the winder so as to maintain the torque generated by the winder in correspondence with the desired torque at the instantaneous radius. Thus, the winder control functions to control the torque generated by the winder to enable the winder to vary the tension on the material to wound 'as a function of the radius of the wound material.

From the above it should be apparent that an object of the present invention is to provide a new and improved winder control for controlling the torque to be applied by a winder to control the tension imparted to material to be wound or unwoundso that a predetermined taper of tension, which is a function of the instantaneous radius of the roll of material, is maintained.

DESCRIPTION or THE DRAWINGS This and other objects of the present invention will become apparent from the following description of a preferred embodiment of the invention taken in conjunction with the accompanying drawings wherein:

FIG. l is a block diagram illustrating the winder or tension control utilized with a current control and an eddy-current drive;

FIG. 2 is a block diagram more fully illustrating the winder or tension control;

FIG. 3 is a schematic diagram of the winder control; and

FIG. 4 is a graph illustrating the torque by a plot of the build up of wound material on the core of the winder plotted against a tension reference.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention provides a winder or tension control system 8 for controlling the tension of material wound on a winder roll 14. To this end, FIG. 1 schematically illustrates the winder roll 14 which receives material to be wound 12 thereon from an unwind roll 18. The material to be wound 12 is processed by a processor 20 as it travels from the unwind roll 18 to the winder roll 14. A drive 16 is provided for driving the winder roll 14. While the drive may be any one of a plurality of known drives, the drive is shown, for illustrative purposes only, as comprising an eddy current drive 16. A tension control 10 provides a signal which effects the energization of the eddy current drive 16 to thereby control the torque applied to the winder roll 14. The torque applied to the winder roll 14 by the drive 16 controls the tension on the material 12 to be wound. The tension is a function of the radius of the wound material on roll 14 and the torque applied by the drive 16. The particular equation which governs the tension on the material 12 to be wound is as follows;

where T the torque, applied to the roll R the radius of the roll and F the tension on the wound material. Thus, if the torque is maintained constant, the tension 'will decrease as the radius increases. It should now be apparent that by controlling the torque generated by the drive 16, the tension on the material to be wound 12 may be controlled when the radius of the wound material is known and accounted for in varying the torque.

The tension control 10 directs a current reference signal along line 28 to a current controller 26. The output of the current controller 26 is directed along line 29 to control the energization of the eddy current drive 16. The current controller 26 may be any one of a plurality of known current controllers and may correspond to the current control disclosed in the OCallaghan US. Pat. No. 3,629,633. The current controller 26 includes a current feedback path 30 and energizes the coil of the eddy current drive 16 in a well known manner to control the torque applied to the winder 14.

A sensing means, preferably a tachometer generator 22 is provided to sense the linear velocity of the material 12 to be wound. The tachometer generator 22 directs a signal indicative of the linear velocity of the material 12 to be wound, along line 32 to the tension control 10. A second sensing means 24, which preferably may be a tachometer generator 24, is associated with the drive 16 and the winder 14 and senses the angular velocity of thewinder 14. The tachometer generator 24 directs a signal along line 34 to the tension control 10. The signal-directed along line 34 is indicative of the angular velocity of the winder 14. The tension control utilizes the angular velocity signal directed along line 34 and the linear velocity signal directed along line 32 tov calculate the instantaneous radius of the wound material 12 on the winder 14. A pair of potentiometers 36 and 38 direct signals along lines 37 and 39 respectively to the tension control 10. The signals established on lines 37 and 39 by the potentiometers 36 and 38 are indicative of the desired tension and taper, respectively, of the material 12 to be wound. The signals established on lines 37 and 39 by the potentiometers 36 and 38 respectively, are combined in the tension control 10 with the signal indicative of the instantaneous radius of the material 12 on the winder 14 to establish a signal to be directed along line 28 to the current controller 26. The signal directed to the current controller 26 is indicative of the instantaneous radius of the roll 14 and the desired tension to be applied to the material to be wound 12. The current controller 26 acts in a well known manner to control the torque generated by the drive 16 in response to the signal on line 28 to thereby control the tension on the material l2 to be wound. While the tension control 10 has been illustrated in conjunction with a current controller 26 it should be appreciated that a suitable torque control could also be utilized in a well known manner.

The tension control, more fully illustrated in FIG. 2, includes an inertia compensation circuit 40, an analog divider circuit 42, a friction compensation circuit 44 and a starting circuit 46. The inertia compensation circuit 40 establishes a torque signal proportional to the acceleration of the material 12 to be wound which signal compensates for system inertia during acceleration or deceleration of the winder 14. The inertia compensation circuit 40 receives a signal from the tachometer 22 which is indicative of line speed. The signal from tachometer 22 is directed through a filter circuit 48 and through a pair of calibration potentiometers 50 and 52 to the inertia compensation circuit 40. The potentiometers 50 and 52 merely act to scale the line speed signal directed to the inertia compensation circuit 40 for a given drive system. The inertia compensation circuit 40 differentiates the line speed signal directed thereto to establish a torque signal proportional to the acceleration of the winder 14. The inertia compensation circuit 40 then directs its torque signal along line 41 to an input terminal of a summing amplifier 54. While the input, in the present embodiment, to the inertia compensation circuit 40 has been illustrated as coming from a tachometer 22, the input thereto could come from a reference signal which has a magnitude proportional to line speed and which is not taken from the tachometer The friction compensation circuit 44 establishes a torque signal which is directed along line 60 to the summing amplifier 54 to compensate for friction in the winder 14. The tachometer 22 directs a signal which is indicative of the velocity of the material 12 through a calibration potentiometer 50 to the friction compensation circuit 44. The friction compensation circuit 44 comprises a potentiometer 58 which scales the modifled signal from the tachometer generator 22 and directs it along line 60 to an input of the summing amplitier 54. Thus, the input to the summing amplifier 54 from the friction compensation circuit 44 will have a value which is indicative of the velocity of the material 14, and which will act to compensate for friction losses which occur in the winder 14. The friction of such a winder varies in response to the angular speed of the reel and to the weight of material currently wound on the reel, both of which are ordinarily related to the outer radius of the wound material. Air friction losses of the reel also depend upon the outer radius of the material wound on the reel. The setting of potentiometer 58 scales the friction compensation signal for a given drive with which the tension control is utilized. While the friction compensation circuit 44 has been illustrated as receiving its input from the tachometer 22, the friction compensation circuit 44 could also receive its input from the tachometer 24. Thus, the input to the friction compensation circuit 44 may be either an input indicative of the linear velocity of the material 12 to be wound of the angular velocity of the wound material 12. In either instance, the signal directed along line 60 to the summing amplifier 54 will act to compensate for friction losses which occur in the winder system. These friction losses result from friction acting on thewinder roll, guide rollers, etc. over which the material to be wound travels.

The start circuit 46 establishes a pulse for breakway torque upon winder start up. The breakaway torque needed for start up is the torque required to overcome static friction when the winder is started. The height of the start pulse is adjustable by a potentiometer 62 and the width of the pulse is maintained constant. The area underneath the pulse is indicative of the energy needed to overcome the static friction of the system upon start up. The start pulse is directed along line 64 to the summing amplifier 54 upon initial starting of the system and overcomes the static friction of the system to enable the system to start smoothly. It should be appreciated that in many systems where a web of thin material is being moved, such as a web of paper, jerky starting of the system could cause the web of material to break. This problem is accordingly overcome by the starting circuit 46. t

The instantaneous radius of the material 12 on the winder 14 is calculated by the analog divider circuit 42. The analog divider circuit includes a first input terminal 66 which is connected through the scaling potentiometer 50 to the tachometer generator 22. The tachometer generator 22 establishes a signal on input terminal 66 which is proportional to the linear velocity of the material to be wound. The analog divider circuit 42 includes a second input terminal 68 which receives a signal thereon from the tachometer generator 24 which is indicative of the angular velocity of the winder 14. The analog divider 42 operates to divide the linear velocity signal by the angular velocity signal and establishes at its output terminal 70 a signal indicative of the instantaneous radius of the wound material 12 on the winder 14. To accomplish this the analog divider 42 produces a sawtooth waveform whose average value or area under the sawtooth waveform is proportional to the ratio of the linear velocity voltage signal to the angular velocity frequency signal. As an example, doubling the linear velocity signal doubles the ramp rate of the sawtooth and the sawtooth height. This doubles the sawtooth triangle area and hence the average value of the divider 42 output. Similarly doubling the angular velocity frequency signal halves the sawtooth triangle base thereby halving the triangle area and hence the average value of the output. The signal on the output terminal 70 of the analog divider 42 is directed to an averaging amplifier 72 which averages the signal and directs it through a taper potentiometer 38, a buffer amplifier 76 and a tension potentiometer 36 to an input terminal of the summing amplifier 54. The output from the analog divider circuit 42 is a sawtooth wave form which necessitates the use of the averaging amplifier 72 in the system. Thus, the output of the averaging amplifier 72 is essentially a DC signal which is indicative of the instantaneous radius of the roll of material 12 on the winder 14. This signal is scaled through the taper potentiometer 38 which programs the winder control to establish the degree of taper of tension, i.e., variance in tension, on the material to be wound as the radius changes. The taper of tension, as will be more fully explained hereinbelow, is a function of the instantaneous radius of the material to be wound. The signal from the taper potentiometer 38 is directed through the buffer amplifier 76 and through the tension potentiometer 36 which scales the signal for the given system to the summing amplifier 54.

An RPM comparator circuit 74 is provided for cutting out the operation of the analog divider 42 at low speeds. This prevents the analog divider from operating in the circuit when the angular velocity signal from the winder shaft generator 24 is very small. At a predetermined low speed, the RPM comparator 74 will cut off the analog divider 42 and apply a constant predetermined potential to the averaging amplifier 72 to prevent the occurrence of erroneous signals from the analog divider 42 at low speeds.

Upon initial energization of the tension control a breakaway pulse will be applied from the start circuit 46 to the input of the summing amplifier 54. Simultaneously, a constant signal will be applied to the summing amplifier 54 by the stall circuit or RPM comparator 74 due to the fact that the core of the winder 14 is not rotating at a speed high enough to cut out the RPM comparator 74. As the speed of rotation of the winder roll 14 increases, the RPM comparator circuit 74 will cut out and the analog divider circuit 42 will produce a signal indicative of the instantaneous radius of the roll of material 12 and direct this signal to the summing amplifier 54 along with signals from the friction compensation circuit 44 and the inertia compensation circuit 40. The signals sent to amplifier 54 will then be summed and directed to the current controller 26. The

signals directed to the current controller will act as a current reference signal to control the energization of the drive 16 to thereby control the tension on the material 12 to be wound.

The operation of the analog divider 42 and the RPM comparator 74 will now be more fully discussed with reference to FIG. 3. The linear'velocity signal from the tachometer generator 22 is directed along lines 32 where it is rectified by a bridge circuit 80 and directed along input line 67 across a filter circuit 48 which, in the present embodiment, comprises a capacitor 48 and through the scaling potentiometer 50 to an input of an operational amplifier 84. A bias voltage is directed to the other input of the operational amplifier 84 from a biasing potentiometer 86. The signal applied through the bias potentiometer 86 cancels the offset voltage in the amplifier 84. The amplifier 84 acts as a current source in that it converts a voltage proportional to the linear speed of the material 12 to a current value to effect charging of a capacitor 88. The output of the operational amplifier 84 charges the capacitor 88 at a rate which is dependent upon the linear velocity of the material 12 to be wound as sensed by the tachometer generator 22.

The tachometer generator 24 directs a signal indicative of the angular velocity of the winder 14 alonglines 34 and through a transformer 35 to input line 69 of the AC to pulse converter 56. The signal on input line 69 is filtered by a filter capacitor 90 and is directed to the base of a transistor 92. The collector of the transistor 92 is connected to an input terminal of a Schmitt trigger 94. Transistor 92 is switched on every time the sinusoidal wave form on input line 69 is high. Switching on of transistor 92 will effect a high output from the Schmitt trigger 94. The transistor 92 acts to produce a gain in the system during low winder speeds whenever the output from the tachometer generator 24 is low. Since the input on line 69 is essentially sinusoidal and the transistor 92 switches from a conductive to a nonconductive condition depending upon the polarity of the sinusoidal signal, the output of the Schmitt trigger 94 essentially forms a square wave. The output of the Schmitt trigger 94 is high when the transistor 92 is on and low when the transistor 92 is nonconductive. The output of the Schmitt trigger 94 is fed along line 68 to the base of an amplifying transistor 96. A high output from Schmitt trigger 94 will cause transistor 96 to momentarily conduct. The emitter of transistor 96 is connected to the base of a transistor 98. Conduction of transistor 96 will effect conduction of transistor 98. Transistor 96 and 98 will momentarily conduct at the leading edge of the pulsating output from the Schmitt trigger 94. The momentary conduction of transistor 98 will control the frequency of wave form 100.

The capacitor 88 is connected between the collector and emitter of transistor 98 and, as stated hereinbefore, is charged by the output of the scaling amplifier 84. The charge directed to the capacitor 88 from the amplifier 84 is produced by a current which is proportional to line speed. Capacitor 88 is discharged by the conduction of the transistor 98. Since the transistor 98 conducts in a cyclical fashion clue to the cyclic conduction of the transistor 92, which conducts at a frequency proportional to the angular velocity of the winder 14, transistor 98 will cyclically cause the capacitor 88 to discharge at a frequency which is dependent upon the angular velocity of the winder 14. The charging of the capacitor 88 by the amplifier 84 and the cyclical discharging of the capacitor 88 by the conduction of the transistor 96 will generate a sawtooth wave form, schematically illustrated as wave form 100 on line 70. The frequency of the sawtooth wave will be controlled by the conduction of the transistor 98 which is proportional to the angular velocity of the winder. The magnitude of the ramp wave form will be proportional to the charge on capacitor 88 which charge is proportional to the linear velocity of the material 12 to be wound. The ramp wave form 100 is directed along line 70 to the input of an averaging amplifier 72. The output of the averaging amplifier 72 will be a signal having a magnitude proportional to the average value of the ramp wave form 100 and as such will be proportional to the instantaneous radius of the wound material.

The output of the averaging amplifier 72 is directed to the taper potentiometer 38 which sets the percent taper of the tension and directs a signal indicative thereof to the input of the buffer amplifier 76. Associated with the taper potentiometer 38 is a taper bias potentiometer 102 which is ganged to the taper potentiometer 38. The taper bias potentiometer 102 applies a constant voltage to the buffer amplifier 76 which provides a taper offset signal dependent upon the build up range of the specific winder system. The taper offset signal is combined with the taper signal from the taper potentiometer 38 at the buffer amplifier 76. The taper bias potentiometer 102 is ganged to the taper potentiometer 38 so that as the percent of taper is reduced by the taper potentiometer 38 the DC taper offset from the taper bias potentiometer 102 is automatically increased to the proper value. Thus, the percent taper signal, which is a function of the setting of the taper potentiometer 38 and the instantaneous radius of the wound material, is fed to one terminal of the buffer amplifier 76 and the taper offset signal, which is a function of the setting of the taper potentiometer 38, is fed from the taper bias potentiometer 102 to the other terminal of the buffer amplifier 76. The two signals are combined in the buffer amplifier 76 and applied through the tension potentiometer 36 to the summing amplifier 54. The tension potentiometer 36 scales the output of the buffer amplifier 76 for a particular tension desired in a specific system and directs the signal to the summing amplifier 54 which sums the signal with the dynamic compensation signals from the friction compensation circuit 44 and the inertia compensation circuit 40. The output of the summing amplifier 54 is directed to the current control 26 to effect energization of the drive 16.

The operation of the system and specifically the taper potentiometer 38 and the taper bias potentiometer 102 will be more fully understood from FIG. 4 which is a plot of the tension reference versus the build up of the material on the core of the winder 14. The curve A illustrates the condition when a constant tension is maintained from initial winding at the core to full build up of the roll of wound material. The curves of FIG. 4 were plotted utilizing the equation that torque equals tension times radius. in curve A the torque applied by the drive 16 when material is initially being wound on the core and has a radius essentially equal to the radius of the core, will be 10 percent of the maximum torque that the drive 16 may apply. As the radius of the roll builds up, the torque will increase to maintain a constant tension on the material to be wound. At full build up of the roll the torque will be 100 percent of the rated torque of the drive 16 and the tension will remain constant. Scaling the curve A by setting the taper potentiometer at 50 percent produces curve B. Curve B shows the uncorrected taper signal without the taper offset normally established by the taper bias potentiometer 102. Curve B keeps the tension at 50 percent from initial core radius to full buildup of material 12. In curve B the percent of torque at the core radius will be 5 percent and the percent of torque at full material 12 buildup will be 50 percent. To achieve taper the signal plotted on curve B is further reduced to 45 percent tension as is shown in curve B. [n curve B" the percent tension at the initial core radius is 45 percent and remains at 45 percent to full material 12 buildup while the percent torque at the initial core radius is 4.5 percent and varies to 45 percent at full material 12 buildup. Thus, B gives us an uncorrected taper signal. To correct the uncorrected taper signal, the taper bias potentiometer 102 is set to apply a constant DC voltage to the buffer amplifier 76 which has a weighted value equal to 5 percent of the desired tension reference curve. Thus, the corrected signal is the sum of the two signals, the constant DC voltage as indicated on curve B and the B curve. These two signals when added together form the reference curve B which is the desired reference curve. Since the two signals for taper are taken from the ganged potentiometers 102 and 38, when the radius signal is reduced via the potentiometer 38 the DC taper offset is automatically increased to the proper value by the bias potentionmeter 102. Thus, the desired taper signal is directed from the taper offset potentiometers to the buffer amplifier 76 and to the main summing amplifier 54 where it is summed along with the other dynamic compensation signals.

The RPM comparator or stall circuit 74, as illustrated in FIG. 3, receives an input along line 104 from the output of the Schmit trigger 94. The input on line 104 is a square wave, having a frequency indicative of the angular velocity of the winder 14, which is applied to the terminals of an AND gate 106. The output of AND gate 106 is connected to the input of a monostable multivibrator 108. The monostable multivibrator 108 includes a pair of output terminals 110 and 112. When the monostable multivibrator is set by a positive portion of the square wave input, the output terminal 110 will be low and the output terminal 112 will be high. The monostable multivibrator 108 functions such that when it is set it automatically resets after a predetermined period of time. If the monostable multivibrator 108 is not set again before it resets, the monostable multivibrator will reset automatically and apply a high signal on the output terminal 110 and a low signal on the output terminal 1 12. The output terminal 1 10 is connected to the base of a transistor 114 and when a high pulse is applied to the base of the transistor 114, the transistor 114 will conduct and cause an indicator light 116 to come on indicating that the unit is at a stall speed. At or below the stall speed the input pulses to the monostable multivibrator 108 are such that the monostable multivibrator 108 will reset itself automatically before being set by the next incoming pulse. The stall speed is the speed at which the angular velocity signal to the analog divider 42 is too small that the divider is not utilized to calculate the instantaneous radius of the material 12 on the winder l4 and the RPM comparator 56 is used to direct a constant reference signal to the buffer amplifier 76 to take the place of the signal from the analog divider 42.

The output terminal 112 of the monostable multivibrator is connected to the base of a transistor 118. When the monostable multivibrator is in its normal or set condition, the output on terminal 112 will be high and the transistor 118 will conduct. The collector of the transistor 118 is tied to the base of a transistor 120 via line 122. Normally when the transistor 118 is conducting and the monostable multivibrator 108 is in its set condition, the conduction of the transistor 118 will prevent the conduction of the transistor 120. However, when the transistor 118 is rendered nonconductive by the resetting of the monostable multivibrator 108 a positive potential will be applied along line 122 from a voltage source 123 to the base of the transistor 120 to effect conduction of the transistor 120. The positive potential applied along line 122 will also be applied to a stall potentiometer 124 which directs a biasing input along line 126 to the input of the amplifier 76. Conduction of the transistor 120 will prevent the application of the cyclic ramp wave 100 on line 70 to the input of operational amplifier 72. The conduction of the transistor 120 will pull line 70 down to ground to prevent the divider 42 from operating in the circuit when the RPM signal from tachometer generator 24 indicates that the core of the winder 14 is rotating at a relatively slow speed. This will prevent the divider from operating in the circuit during a stall condition. When the transistor 120 is conductive, the stall potentiometer 124 will apply a potential along line 126 to the amplifier 76 to take the place of the radius signal normally applied to amplifier 76. The signal applied by the stall potentiometer 124 will be a constant signal which represents a constant artificial radius when the analog divider 42 is not operating due to the angular velocity of the system being too low.

From the foregoing it should be apparent that a new and improved winder control has been provided by the present invention. The winder control includes a tension control which senses the linear velocity of the material to be wound and the angular velocity of the material to be wound and which divides the linear velocity by the angular velocity to determine the instantaneous radius of the wound material. The instantaneous radius signal is fed through taper setting potentiometers which determine the percent of taper of tension of the wound roll and through a tension potentiometer to a main summing amplifier. The main summing amplifier also includes inputs from an inertia compensation circuit which compensates for the inertia of the winder during acceleration and an input from a friction compensation circuit which compensates for the friction of the winder at different speeds thereof. The inertia compensation signal, friction compensation signal and the tension signal which is proportional to the instantaneous radius of the wound material are summed by the summing amplifier and directed to a current control which operates in a well known manner to control the drive of the system. In this manner an inexpensive yet reliable and accurate drive system has been provided for accurately controlling the taper of tension on a roll of wound material.

While the preferred embodiment of the present invention has been illustrated as a control for controlling the tension on material to be wound, it should be readily appreciated that the present invention could also be utilized to control the tension on material being unwound from a roll of materialv What we claim is:

l. A control for maintaining a predetermined tension on material being transferred between a source of ma terial and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the 'roll of material and establishing a first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, means including a divider means responsive to said second signal and said first signal for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll, said divider means being responsive to said first and second sensing means to establish a cyclic sawtooth wave form having a frequency dependent upon the angular velocity of the roll of material and a ramp magnitude dependent upon the linear velocity of the material, said means for establishing said cyclic wave form including means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, and said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.

2. A control for maintaining a predetermined tension on material being transferred between a source of ma terial and a roll as defined in claim 1 further including averaging means for establishing said radius signal which has a magnitude indicative of the average value of said cyclic wave form and taper and taper-bias potentiometers ganged together for setting the taper and taper-bias of the material being transferred, said taper potentionmeter modifying said radius signal indicative of the average value of said cyclic wave form and said taper-bias potentiometer establishing a constant biasing signal having a value indicative of the setting of said taper potentiometer and directing said biasing signal to said summing means.

3. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means responsive to said linear velocity signal and said angular velocity signal for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsiveto the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means.

4. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the roll of material and establishing a first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, dynamic compensation means for establishing a dynamic compensating signal, means including a divider means for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for summing said instantaneous radius signal and said dynamic compensation signal and establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll and comparator means responsive to said first sensing means to render said divider means inoperative at a predetermined angular velocity of said roll of material, and wherein said comparator means responsive to the angular velocity of said roll of wound material generates a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, divider means includes means responsive to said first and second sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.

5. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll as defined in claim 4 wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is belowa predetermined level, cut out means responsive to said control signal for preventing said radius signal from being directed to said summing means when the angular velocity of the winder roll is below a predetermined level and means for directing said constant radius reference signal generated by said comparator means to said summing means when said cut out means is energized and said radius signal is prevented from being directed to said summing means.

6. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll as defined in claim 5 wherein said dynamic compensation means includes a friction compensation means for compensating for friction in the winder and inertia compensation means for compensating for the inertia of the winder and the material being transferred, said friction compensation means including means responsive to said second signal for establishing a friction compensation signal dependent upon the linear velocity of the material being transferred and operative to direct said friction compensation to said summing means, said inertia compensation means including means responsive to said second signal for establishing an inertia compensation signal dependent upon the linear velocity of the material being transferred and operative to direct said inertia compensation signal to said summing means.

7. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means responsive to said linear velocity signal and said angular velocity signal for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said divider means includes means responsive to said first and second sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for pcriodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.

8. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll as defined in claim 7 further including averaging means for establishing said radius signal which has a magnitude indicative of the average value of said cyclic wave form and taper and taper-bias potentiometers ganged together for setting the taper and taper-bias of the material being transferred, said taper potentionmeter modifying said radius signal indicative of the average value of said cyclic wave form and said taper-bias potentionmeter establishing a constant biasing signal having a value indicative of the setting of said taper potentiometer and directing said biasing signal to said summing means.

9. An open-loop control for maintaining the tension on a filament of material which is being transferred between a source of material and a roll in correspondence with a predetermined tension which is dependent upon the instantaneous radius of the roll of material comprising drive means for driving the roll of material, a tension control means for establishing a reference signal indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius, a control circuit responsive to the reference signal of said tension control means and being connected to said drive means for energizing said drive means to maintain the predetermined tension on said filmanet of material, first sensing means for sensing the angular velocity of the roll of material and establishing an angular velocity signal indicative thereof and second sensing means for sensing the linear velocity of the filament of material for establishing a linear velocity signal indicative thereof, said tension control means being responsive to said angular velocity signal and said linear velocity signal and including means having a divider circuit for establishing a radius signal indicative of the instantaneous radius of the roll of material and means for modifying said radius signal to establish said reference signal which is indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said divider means includes means responsive to said first sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.

10. A control for maintaining the tension in a filament of material which is being transferred between a source of material and a roll in correspondence with a predetermined tension as defined in claim 9 wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing the establishment of said radius signal when the angular velocity of the winder roll is below a predetermined level and means for establishing said constant radius reference signal when said cut out means is energized.

11. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the roll of material and establishing a periodic first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, dynamic compensation means for establishing a dynamic compensating signal, means including a divider means for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for summing said instantaneous radius signal and said dynamic compensation signal and establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll and comparator means responsive to said first sensing means to render said divider means inoperative at a predetermined angular velocity of said roll of material, and wherein said comparator means responsive to the angular velocity of said roll of wound material generates a constant radius reference sngial when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing said instantaneous radius signal from being directed, to said summing means when the angular velocity of the winder roll is below a predetermined level, and means for directing said constant radius reference signal generated by said comparator means to said summing means when said cut out means is energize d and said instantaneous radius signal is prevented from being directed to said summing means, wherein said means responsive to said first sensing means for establishing said control signal includes monostable multivibrator means for establishing a reference period for comparison with the period of said periodic first signal, said reference period corresponding to the angular velocity of said winder roll at said predetermined level, and further includes circuit means for producing said control signal when said period of said periodic first signal is below said reference period.

12. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing a periodic angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means responsive to said linear velocity signal and said angular velocity signal for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein saidcomparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing said radius signal from being directed to said summing means when the angular velocity of the winder roll is below a predetermined level and means for establishing said constant radius reference signal and directing said constant radius reference signal to said summing means when said cut out means is energized and said radius signal is prevented from being directed to said summing means, and wherein said means responsive to said first sensing means for establishing said control signal includes monostable multivibrator means for establishing a reference period for comparison with the period of said periodic angular velocity signal, said reference period corresponding to the angular velocity of said winder roll at said predetermined level, and further includes circuit means for producing said control signal when said period of said periodic angular velocity signal is below said reference period.

13. An open-loop control for maintaining the tension on a filament of material which is being transferred between a source of material and a roll in correspondence with a predetermined tension which is dependent upon the instantaneous radius of the roll of material comprising drive means for driving the roll of material, a tension control means for establishing a reference signal indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius, a control circuit responsive to the reference signal of said tension control means and being connected to said drive means for energizing said drive means to maintain the predetermined tension on said filament of material, first sensing means for sensing the angular velocity of the roll of material and establishing a periodic angular velocity signal indicative thereof and second sensing means for sensing the linear velocity of the filament of material for establishing a linear velocity signal indicative thereof, said tension control means being responsive to said angular velocity signal and said linear velocity signal and including means having a divider circuit for establishing a radius signal indicative of the instantaneous radius of the roll of material and means for modifying said radius signal to establish said reference signal which is indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inop.- erative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level,

cut out means responsive to said control signal for pre venting the establishment of said radius signal when the angular velocity of the winder roll is below a predetermined level and means for establishing said constant radius reference signal when said cut out means is energized, and wherein said means responsive to said first period corresponding to the angular velocity of said winder roll at said predetermined level, and further includes circuit means for producing said control signal when said period of said periodic angular velocity signal is below said reference period.

14. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and wherein said divider means includes means responsive to said first and second sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.

15. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll as defined in claim 14 further including averaging means for establishing said radius signal which has a magnitude indicative of the average value of said cyclic wave form and taper and taper-bias potentiometers ganged together for setting the taper and taper-bias of the material being transferred, said taper potentiometer modifying said radius signal indicative of the average value of said cyclic wave form and said taper-bias potentiometer establishing a constant biasing signal having a value indicative of the setting of said taper potentiometer and directing said biasing signal to said summing means.

16. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the roll of material and establishing a first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, dynamic compensation means for establishing a dynamic compensation signal, means including a divider means for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for summing said instantaneous radius signal and said dynamic compensation signal and establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll and comparator means responsive to said first sensing means to render said divider means inoperative at a predetermined angular velocity of said roll of material, and wherein said dynamic compensation means includes friction compensation means for compensating for friction in the winder, said friction compensation means including means responsive to said second signal for establishing a friction compensation signal dependent upon the linear velocity of the material being transferred and operative to direct said friction compensation signal to said summing means.

17. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, including divider means for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material.

* l l l UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT N0. 1 10,521

DATED 10/7/75 INVIENTOR(S) G. F. O'Callaghan; J.1 1.Haurykiewi It is certified that error appearsin the above-identified patent and that said Letters Patent are hereby corrected as shownbelow:

Col. 13, line 29: Correct spelling of "potentianeter".

line 31,32: Correct spelling of "potentiometer".

line 49: Correct spelling of "filament".

Col. 14, line 64: Correct spelling of "signal".

Col. 18, line 49: Insert "means after "transferred".

Signed and Scaled this A ttes t:

RUTH C. MASON C. MAR Arrestin Offi HALL DANN ommissimzvr oj'Patents and Trademarks UNITED STATES PATENT AND T ADEMARK OFF-ICE CERTIFICATE OF CORRECTION PATENT NO. 3,910,521

DATED 10/7/75 ]N\/ENTOR($) G. F. OCallaghan; J.1 I.Haurykiew:i.cz

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

line 31,32: Correct spelling of "potenticxneter".

line 49: Correct spelling of "filament".

Col. 14, line 64: Correct spelling of "signal".

Col. 18, line 49: Insert "means' after "transferred".

Signed and Scaled ttu's [SEAL] sixteenth Day of March1976 A ttes t:

RUTH C. MASON C. MARSH Anesrin Offi ALL DANN ummissimwr of Parents and Trademarks 

1. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the roll of material and establishing a first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, means including a divider means responsive to said second signal and said first signal for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll, said divider means being responsive to said first and second sensing means to establish a cyclic sawtooth wave form having a frequency dependent upon the angular velocity of the roll of material and a ramp magnitude dependent upon the linear velocity of the material, said means for establishing said cyclic wave form including means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, and said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.
 2. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll as defined in claim 1 further including averaging means for establishing said radius signal which has a magnitude indicative of the average value of said cyclic wave form and taper and taper-bias potentiometers ganged together for setting the taper and taper-bias of the material being transferred, said taper potentionmeter modifying said radius signal indicative of the average value of said cyclic wave form and said taper-bias potentiometer establishing a constant biasing signal having a value indicative of the setting of said taper potentiometer and directing said biasing signal to said summing means.
 3. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tensIon to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means responsive to said linear velocity signal and said angular velocity signal for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means.
 4. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the roll of material and establishing a first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, dynamic compensation means for establishing a dynamic compensating signal, means including a divider means for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for summing said instantaneous radius signal and said dynamic compensation signal and establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll and comparator means responsive to said first sensing means to render said divider means inoperative at a predetermined angular velocity of said roll of material, and wherein said comparator means responsive to the angular velocity of said roll of wound material generates a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, divider means includes means responsive to said first and second sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storAge means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.
 5. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll as defined in claim 4 wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing said radius signal from being directed to said summing means when the angular velocity of the winder roll is below a predetermined level and means for directing said constant radius reference signal generated by said comparator means to said summing means when said cut out means is energized and said radius signal is prevented from being directed to said summing means.
 6. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll as defined in claim 5 wherein said dynamic compensation means includes a friction compensation means for compensating for friction in the winder and inertia compensation means for compensating for the inertia of the winder and the material being transferred, said friction compensation means including means responsive to said second signal for establishing a friction compensation signal dependent upon the linear velocity of the material being transferred and operative to direct said friction compensation to said summing means, said inertia compensation means including means responsive to said second signal for establishing an inertia compensation signal dependent upon the linear velocity of the material being transferred and operative to direct said inertia compensation signal to said summing means.
 7. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means responsive to said linear velocity signal and said angular velocity signal for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal wHen the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said divider means includes means responsive to said first and second sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.
 8. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll as defined in claim 7 further including averaging means for establishing said radius signal which has a magnitude indicative of the average value of said cyclic wave form and taper and taper-bias potentiometers ganged together for setting the taper and taper-bias of the material being transferred, said taper potentionmeter modifying said radius signal indicative of the average value of said cyclic wave form and said taper-bias potentionmeter establishing a constant biasing signal having a value indicative of the setting of said taper potentiometer and directing said biasing signal to said summing means.
 9. An open-loop control for maintaining the tension on a filament of material which is being transferred between a source of material and a roll in correspondence with a predetermined tension which is dependent upon the instantaneous radius of the roll of material comprising drive means for driving the roll of material, a tension control means for establishing a reference signal indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius, a control circuit responsive to the reference signal of said tension control means and being connected to said drive means for energizing said drive means to maintain the predetermined tension on said filmanet of material, first sensing means for sensing the angular velocity of the roll of material and establishing an angular velocity signal indicative thereof and second sensing means for sensing the linear velocity of the filament of material for establishing a linear velocity signal indicative thereof, said tension control means being responsive to said angular velocity signal and said linear velocity signal and including means having a divider circuit for establishing a radius signal indicative of the instantaneous radius of the roll of material and means for modifying said radius signal to establish said reference signal which is indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein sAid divider means includes means responsive to said first sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.
 10. A control for maintaining the tension in a filament of material which is being transferred between a source of material and a roll in correspondence with a predetermined tension as defined in claim 9 wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing the establishment of said radius signal when the angular velocity of the winder roll is below a predetermined level and means for establishing said constant radius reference signal when said cut out means is energized.
 11. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the roll of material and establishing a periodic first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, dynamic compensation means for establishing a dynamic compensating signal, means including a divider means for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for summing said instantaneous radius signal and said dynamic compensation signal and establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll and comparator means responsive to said first sensing means to render said divider means inoperative at a predetermined angular velocity of said roll of material, and wherein said comparator means responsive to the angular velocity of said roll of wound material generates a constant radius reference sngial when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing said instantaneous radius signal from being directed to said summing means when the angular velocity of the winder roll is below a predetermined level, and means for directing said constant radius reference signal generated by said comparator means to said summing means when said cut out means is energized and said instantaneous radius signal is prevented from being directed to said summing means, wherein said means responsive to said first sensing means for establishing said control signal includes monostabLe multivibrator means for establishing a reference period for comparison with the period of said periodic first signal, said reference period corresponding to the angular velocity of said winder roll at said predetermined level, and further includes circuit means for producing said control signal when said period of said periodic first signal is below said reference period.
 12. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing a periodic angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means responsive to said linear velocity signal and said angular velocity signal for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing said radius signal from being directed to said summing means when the angular velocity of the winder roll is below a predetermined level and means for establishing said constant radius reference signal and directing said constant radius reference signal to said summing means when said cut out means is energized and said radius signal is prevented from being directed to said summing means, and wherein said means responsive to said first sensing means for establishing said control signal includes monostable multivibrator means for establishing a reference period for comparison with the period of said periodic angular velocity signal, said reference period corresponding to the angular velocity of said winder roll at said predetermined level, and further includes circuit means for producing said control signal when said period of said periodic angular velocity signal is below said reference period.
 13. An open-loop control for maintaining the tension on a filament of material which is being transferred between a source of material and a roll in correspondence with a predetermined tension which is dependent upon the instantaneous radius of the roll of matErial comprising drive means for driving the roll of material, a tension control means for establishing a reference signal indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius, a control circuit responsive to the reference signal of said tension control means and being connected to said drive means for energizing said drive means to maintain the predetermined tension on said filament of material, first sensing means for sensing the angular velocity of the roll of material and establishing a periodic angular velocity signal indicative thereof and second sensing means for sensing the linear velocity of the filament of material for establishing a linear velocity signal indicative thereof, said tension control means being responsive to said angular velocity signal and said linear velocity signal and including means having a divider circuit for establishing a radius signal indicative of the instantaneous radius of the roll of material and means for modifying said radius signal to establish said reference signal which is indicative of the instantaneous radius of the roll of material and the desired tension to be applied to the filament at the instantaneous radius and comparator means responsive to the angular velocity of said roll of wound material for rendering said divider means inoperative to generate said radius signal when the angular velocity of the roll of material is below a predetermined minimum value, said comparator means generating a constant radius reference signal when said divider means is rendered inoperative, said comparator means directing said constant reference radius signal to said summing means, and wherein said comparator means includes means responsive to said first sensing means for establishing a control signal when the angular velocity of the winder roll is below a predetermined level, cut out means responsive to said control signal for preventing the establishment of said radius signal when the angular velocity of the winder roll is below a predetermined level and means for establishing said constant radius reference signal when said cut out means is energized, and wherein said means responsive to said first sensing means for establishing said control signal includes monostable multivibrator means for establishing a reference period for comparison with the period of said periodic angular velocity signal, said reference period corresponding to the angular velocity of said winder roll at said predetermined level, and further includes circuit means for producing said control signal when said period of said periodic angular velocity signal is below said reference period.
 14. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, means including divider means for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the iNstantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material, and wherein said divider means includes means responsive to said first and second sensing means for establishing a cyclic wave form having a frequency dependent upon the angular velocity of the roll of material and a magnitude dependent upon the linear velocity of the material, and wherein said means for establishing said cyclic wave form includes means responsive to said second sensing means for generating a current signal having a magnitude dependent upon the linear velocity of the material, energy storage means responsive to said current signal for storing energy having a magnitude which is dependent upon the magnitude of said current signal and switching means for periodically discharging said energy storage means to establish said cyclic wave form, said switching means acting to periodically discharge said energy storage means at a frequency which is dependent upon the angular velocity of the roll of material.
 15. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maintain a predetermined tension on material being transferred between a source of material and a roll as defined in claim 14 further including averaging means for establishing said radius signal which has a magnitude indicative of the average value of said cyclic wave form and taper and taper-bias potentiometers ganged together for setting the taper and taper-bias of the material being transferred, said taper potentiometer modifying said radius signal indicative of the average value of said cyclic wave form and said taper-bias potentiometer establishing a constant biasing signal having a value indicative of the setting of said taper potentiometer and directing said biasing signal to said summing means.
 16. A control for maintaining a predetermined tension on material being transferred between a source of material and a roll wherein the predetermined tension is dependent upon the instantaneous radius of the roll of material comprising, first sensing means for sensing the angular velocity of the roll of material and establishing a first signal indicative of the angular velocity of the roll of material, second sensing means for sensing the linear velocity of the material and establishing a second signal indicative of the linear velocity of the material, dynamic compensation means for establishing a dynamic compensation signal, means including a divider means for establishing a radius signal indicative of the instantaneous radius of the roll of wound material, summing means for summing said instantaneous radius signal and said dynamic compensation signal and establishing a control signal indicative of the desired tension to be applied to said material, drive means for driving said roll of material, control means responsive to said control signal for energizing said drive means to maintain a predetermined tension on said material which tension is dependent upon the instantaneous radius of the material on the roll and comparator means responsive to said first sensing means to render said divider means inoperative at a predetermined angular velocity of said roll of material, and wherein said dynamic compensation means includes friction compensation means for compensating for friction in the winder, said friction compensation means including means responsive to said second signal for establishing a friction compensation signal dependent upon the linear velocity of the material being transferred and operative to direct said friction compensation signal to said summing means.
 17. A winder control for generating a signal indicative of the instantaneous torque to be applied by a winder to maIntain a predetermined tension on material being transferred between a source of material and a roll wherein the torque to be applied by the winder is dependent upon the instantaneous radius of the wound material on the roll and the desired tension to be applied to the material being transferred which varies with the radius of the wound material, said control comprising first sensing means for establishing an angular velocity signal indicative of the angular velocity of the wound material, second sensing means for establishing a linear velocity signal indicative of the linear velocity of the material being transferred, including divider means for establishing a radius signal indicative of the instantaneous radius of the wound material, inertia compensation means for establishing an inertia compensation signal dependent upon acceleration of the winder for compensating for inertia of the winder during acceleration, friction compensation means responsive to the linear velocity of the material being transferred for establishing a friction compensation signal indicative of the friction acting on the winder at a given velocity, summing means for summing said radius signal indicative of the instantaneous radius of the wound material, said friction compensation signal and said inertia compensation signal establishing a control signal indicative of the torque to be applied by the winder to the material being transferred to maintain a predetermined tension on the material being transferred which is dependent on the instantaneous radius of the wound material. 